Sofa



FIG. 1 is a top view of a sofa of the claimed design;

FIG. 2 is a back view of the sofa shown in FIG. 1; and,

FIG. 3 is a left side view of the sofa shown in FIG. 1.

The ornamental design which is claimed is shown in the figures. Any colors and surface textures shown in the figures are not part of the claimed design. 

CLAIM I claim the ornamental design for a sofa, as shown and described. 